Event Plot

Produces an activity or a tempo plot.

Usage

# S4 method for class 'EventDate,missing'
plot(
  x,
  type = c("activity", "tempo"),
  event = FALSE,
  calendar = getOption("kairos.calendar"),
  select = 1,
  n = 500,
  eps = 1e-09,
  col.accumulation = "black",
  col.event = "red",
  flip = FALSE,
  ncol = NULL,
  xlab = NULL,
  ylab = NULL,
  main = NULL,
  sub = NULL,
  ann = graphics::par("ann"),
  axes = TRUE,
  frame.plot = axes,
  ...
)

Arguments

x: An EventDate object.
type: A character string indicating the type of plot. It must be one of "activity" (default) or "tempo" (see details). Any unambiguous substring can be given.
event: A logical scalar: should the distribution of the event date be displayed? Only used if type is "activity".
calendar: An aion::TimeScale object specifying the target calendar (see calendar()).
select: A numeric or character vector giving the selection of the assemblage that are drawn.
n: A length-one non-negative numeric vector giving the desired length of the vector of quantiles for density computation.
eps: A length-one numeric value giving the cutoff below which values will be removed.
col.accumulation: A color specification for the accumulation density curve.
col.event: A color specification for the event density curve.
flip: A logical scalar: should the y-axis (ticks and numbering) be flipped from side 2 (left) to 4 (right) from series to series when facet is "multiple"?
ncol: An integer specifying the number of columns to use when facet is "multiple". Defaults to 1 for up to 4 series, otherwise to 2.
xlab, ylab: A character vector giving the x and y axis labels.
main: A character string giving a main title for the plot.
sub: A character string giving a subtitle for the plot.
ann: A logical scalar: should the default annotation (title and x and y axis labels) appear on the plot?
axes: A logical scalar: should axes be drawn on the plot?
frame.plot: A logical scalar: should a box be drawn around the plot?
...: Further parameters to be passed to panel (e.g. graphical parameters).

Value

plot() is called it for its side-effects: it results in a graphic being displayed (invisibly returns x).

Event and Acccumulation Dates

plot() displays the probability estimate density curves of archaeological assemblage dates (event and accumulation dates; Bellanger and Husi 2012). The event date is plotted as a line, while the accumulation date is shown as a grey filled area.

The accumulation date can be displayed as a tempo plot (Dye 2016) or an activity plot (Philippe and Vibet 2020):

tempo: A tempo plot estimates the cumulative occurrence of archaeological events, such as the slope of the plot directly reflects the pace of change.
activity: An activity plot displays the first derivative of the tempo plot.

References

Bellanger, L. & Husi, P. (2012). Statistical Tool for Dating and Interpreting Archaeological Contexts Using Pottery. Journal of Archaeological Science, 39(4), 777-790. doi:10.1016/j.jas.2011.06.031 .

Dye, T. S. (2016). Long-Term Rhythms in the Development of Hawaiian Social Stratification. Journal of Archaeological Science, 71, 1-9. doi:10.1016/j.jas.2016.05.006 .

Philippe, A. & Vibet, M.-A. (2020). Analysis of Archaeological Phases Using the R Package ArchaeoPhases. Journal of Statistical Software, Code Snippets, 93(1), 1-25. doi:10.18637/jss.v093.c01 .

Author

N. Frerebeau

Examples

## Data from Peeples and Schachner 2012
data("zuni", package = "folio")

## Assume that some assemblages are reliably dated (this is NOT a real example)
zuni_dates <- c(
  LZ0569 = 1097, LZ0279 = 1119, CS16 = 1328, LZ0066 = 1111,
  LZ0852 = 1216, LZ1209 = 1251, CS144 = 1262, LZ0563 = 1206,
  LZ0329 = 1076, LZ0005Q = 859, LZ0322 = 1109, LZ0067 = 863,
  LZ0578 = 1180, LZ0227 = 1104, LZ0610 = 1074
)

## Model the event and accumulation date for each assemblage
model <- event(zuni, zuni_dates, rank = 10)
plot(model, select = 1:10, event = TRUE, flip = TRUE)